Cathode Ray Oscilloscope or simply CRO is an electronic instrument which provides visual representation or graph of any waveform applied to its input terminals.
Deflection system is a combination of both the pairs of horizontal and vertical deflection plates. Both the horizontal and vertical plates are kept right angle to each other. When a positive voltage is applied to the horizontal plate, it will deflect the beam towards right(+X axis), while a negative voltage applied to horizontal plate will be deflected towards left(-X axis). Like the same way when positive voltage is applied to vertical plate, it will be deflected on +y axis and negative voltage will be deflected towards -Y axis.
The Fluorescent screen is coated with thin layer of Zinc Oxide. When the electron beam is allowed to strike the phosphor, a spot of light is produced. Phosphor absorbs kinetic energy from electrons that strike it and emits the same energy is emitted in the form of light.
[Top: Input signal as a function of time, Middle: Output signal as a function of time. Bottom: resulting Lissajous curve when output is plotted as a function of the input. In this particular example, because the output is 90 degrees out of phase from the input, the Lissajous curve is a circle.]
In CRO, X-Y mode plot plots signal of (channel 1 ~ channel 2).
Working principle of CRO
Cathode Ray Tube or CRT is the main part or heart of a CRO. It is used to bombard electrons towards the fluorescent screen. CRT is an evacuated tube where an electron gun is fitted, which emits electrons towards the fluorescent screen. In CRT, the electrons are emitted from a hot cathode due to thermionic emission. Control grid determines the amount of electron flow.Deflection system is a combination of both the pairs of horizontal and vertical deflection plates. Both the horizontal and vertical plates are kept right angle to each other. When a positive voltage is applied to the horizontal plate, it will deflect the beam towards right(+X axis), while a negative voltage applied to horizontal plate will be deflected towards left(-X axis). Like the same way when positive voltage is applied to vertical plate, it will be deflected on +y axis and negative voltage will be deflected towards -Y axis.
The Fluorescent screen is coated with thin layer of Zinc Oxide. When the electron beam is allowed to strike the phosphor, a spot of light is produced. Phosphor absorbs kinetic energy from electrons that strike it and emits the same energy is emitted in the form of light.
Lissajous figure
It is the graph of a system of parametric equations
which describe complex harmonic motion.
